drivers/md/raid6sse1.c

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright 2002 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8  *   Bostom MA 02111-1307, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 /*
  14  * raid6sse1.c
  15  *
  16  * SSE-1/MMXEXT implementation of RAID-6 syndrome functions
  17  *
  18  * This is really an MMX implementation, but it requires SSE-1 or
  19  * AMD MMXEXT for prefetch support and a few other features.  The
  20  * support for nontemporal memory accesses is enough to make this
  21  * worthwhile as a separate implementation.
  22  */
  23
  24 #if defined(__i386__) && !defined(__arch_um__)
  25
  26 #include "raid6.h"
  27 #include "raid6x86.h"
  28
  29 /* Defined in raid6mmx.c */
  30 extern const struct raid6_mmx_constants {
  31         u64 x1d;
  32 } raid6_mmx_constants;
  33
  34 static int raid6_have_sse1_or_mmxext(void)
  35 {
  36         /* Not really boot_cpu but "all_cpus" */
  37         return boot_cpu_has(X86_FEATURE_MMX) &&
  38                 (boot_cpu_has(X86_FEATURE_XMM) ||
  39                  boot_cpu_has(X86_FEATURE_MMXEXT));
  40 }
  41
  42 /*
  43  * Plain SSE1 implementation
  44  */
  45 static void raid6_sse11_gen_syndrome(int disks, size_t bytes, void **ptrs)
  46 {
  47         u8 **dptr = (u8 **)ptrs;
  48         u8 *p, *q;
  49         int d, z, z0;
  50
  51         z0 = disks - 3;         /* Highest data disk */
  52         p = dptr[z0+1];         /* XOR parity */
  53         q = dptr[z0+2];         /* RS syndrome */
  54
  55         kernel_fpu_begin();
  56
  57         asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
  58         asm volatile("pxor %mm5,%mm5"); /* Zero temp */
  59
  60         for ( d = 0 ; d < bytes ; d += 8 ) {
  61                 asm volatile("prefetchnta %0" : : "m" (dptr[z0][d]));
  62                 asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
  63                 asm volatile("prefetchnta %0" : : "m" (dptr[z0-1][d]));
  64                 asm volatile("movq %mm2,%mm4"); /* Q[0] */
  65                 asm volatile("movq %0,%%mm6" : : "m" (dptr[z0-1][d]));
  66                 for ( z = z0-2 ; z >= 0 ; z-- ) {
  67                         asm volatile("prefetchnta %0" : : "m" (dptr[z][d]));
  68                         asm volatile("pcmpgtb %mm4,%mm5");
  69                         asm volatile("paddb %mm4,%mm4");
  70                         asm volatile("pand %mm0,%mm5");
  71                         asm volatile("pxor %mm5,%mm4");
  72                         asm volatile("pxor %mm5,%mm5");
  73                         asm volatile("pxor %mm6,%mm2");
  74                         asm volatile("pxor %mm6,%mm4");
  75                         asm volatile("movq %0,%%mm6" : : "m" (dptr[z][d]));
  76                 }
  77                 asm volatile("pcmpgtb %mm4,%mm5");
  78                 asm volatile("paddb %mm4,%mm4");
  79                 asm volatile("pand %mm0,%mm5");
  80                 asm volatile("pxor %mm5,%mm4");
  81                 asm volatile("pxor %mm5,%mm5");
  82                 asm volatile("pxor %mm6,%mm2");
  83                 asm volatile("pxor %mm6,%mm4");
  84
  85                 asm volatile("movntq %%mm2,%0" : "=m" (p[d]));
  86                 asm volatile("movntq %%mm4,%0" : "=m" (q[d]));
  87         }
  88
  89         asm volatile("sfence" : : : "memory");
  90         kernel_fpu_end();
  91 }
  92
  93 const struct raid6_calls raid6_sse1x1 = {
  94         raid6_sse11_gen_syndrome,
  95         raid6_have_sse1_or_mmxext,
  96         "sse1x1",
  97         1                       /* Has cache hints */
  98 };
  99
 100 /*
 101  * Unrolled-by-2 SSE1 implementation
 102  */
 103 static void raid6_sse12_gen_syndrome(int disks, size_t bytes, void **ptrs)
 104 {
 105         u8 **dptr = (u8 **)ptrs;
 106         u8 *p, *q;
 107         int d, z, z0;
 108
 109         z0 = disks - 3;         /* Highest data disk */
 110         p = dptr[z0+1];         /* XOR parity */
 111         q = dptr[z0+2];         /* RS syndrome */
 112
 113         kernel_fpu_begin();
 114
 115         asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
 116         asm volatile("pxor %mm5,%mm5"); /* Zero temp */
 117         asm volatile("pxor %mm7,%mm7"); /* Zero temp */
 118
 119         /* We uniformly assume a single prefetch covers at least 16 bytes */
 120         for ( d = 0 ; d < bytes ; d += 16 ) {
 121                 asm volatile("prefetchnta %0" : : "m" (dptr[z0][d]));
 122                 asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
 123                 asm volatile("movq %0,%%mm3" : : "m" (dptr[z0][d+8])); /* P[1] */
 124                 asm volatile("movq %mm2,%mm4"); /* Q[0] */
 125                 asm volatile("movq %mm3,%mm6"); /* Q[1] */
 126                 for ( z = z0-1 ; z >= 0 ; z-- ) {
 127                         asm volatile("prefetchnta %0" : : "m" (dptr[z][d]));
 128                         asm volatile("pcmpgtb %mm4,%mm5");
 129                         asm volatile("pcmpgtb %mm6,%mm7");
 130                         asm volatile("paddb %mm4,%mm4");
 131                         asm volatile("paddb %mm6,%mm6");
 132                         asm volatile("pand %mm0,%mm5");
 133                         asm volatile("pand %mm0,%mm7");
 134                         asm volatile("pxor %mm5,%mm4");
 135                         asm volatile("pxor %mm7,%mm6");
 136                         asm volatile("movq %0,%%mm5" : : "m" (dptr[z][d]));
 137                         asm volatile("movq %0,%%mm7" : : "m" (dptr[z][d+8]));
 138                         asm volatile("pxor %mm5,%mm2");
 139                         asm volatile("pxor %mm7,%mm3");
 140                         asm volatile("pxor %mm5,%mm4");
 141                         asm volatile("pxor %mm7,%mm6");
 142                         asm volatile("pxor %mm5,%mm5");
 143                         asm volatile("pxor %mm7,%mm7");
 144                 }
 145                 asm volatile("movntq %%mm2,%0" : "=m" (p[d]));
 146                 asm volatile("movntq %%mm3,%0" : "=m" (p[d+8]));
 147                 asm volatile("movntq %%mm4,%0" : "=m" (q[d]));
 148                 asm volatile("movntq %%mm6,%0" : "=m" (q[d+8]));
 149         }
 150
 151         asm volatile("sfence" : :: "memory");
 152         kernel_fpu_end();
 153 }
 154
 155 const struct raid6_calls raid6_sse1x2 = {
 156         raid6_sse12_gen_syndrome,
 157         raid6_have_sse1_or_mmxext,
 158         "sse1x2",
 159         1                       /* Has cache hints */
 160 };
 161
 162 #endif